The invention relates generally to a sensor system and more particularly, to a sensor system for measuring operating parameters of an object in a harsh environment.
Moving objects in rotating machinery, for example, blades in an aircraft engine or blade in a compressor, may experience stresses during operation in a harsh environment. Even stationary objects of machines, for example, combustion liners, nozzles or shrouds may experience stresses or strain due to extreme working conditions such as in a hot gas path or sub zero temperature conditions. Such stresses or strain developed in the objects may damage the machinery. Accurate measurement of operating parameters of the objects, such as temperature and strain, is necessary to correct or prevent any damage that may occur in the machinery. One approach to measuring operating parameters in the machinery is to use wired sensors, which require wiring between a rotating component and a stationary part of the rotary machinery using slip rings. However, a wired approach may be complex, expensive, and unreliable, due in part to the high temperature of the machinery in long-term operation, as the electronic characteristics of the wiring may limit the range of temperatures over which a wired sensor may operate accurately.
Due to the above-mentioned limitations of wired sensors, operating parameter measurements of a machine may only be taken during testing of the machinery. However, monitoring operating parameters over the entire lifespan of the machinery is desirable to ensure reliable operation. Operating parameter measurements taken in the field may be correlated with control parameters to optimize field operation of the machinery. Changes observed in operating parameter measurements over time may be also used to assess the health of the objects or components of the machinery, allowing for appropriate maintenance scheduling. Accordingly, there remains a need in the art for a harsh environment sensor system that is accurate over a wide range of temperatures and conditions, and that may be used over the lifespan of the machinery. It is also desired that this harsh environment sensor system work wirelessly at high temperatures over 500 F, where conventional electronics is not very reliable.